Question 1

Which of the following is not an effect of epinephrine throughout the body?

Accepted Answer

A)   Promotes the breakdown of glycogen in skeletal muscle cells
B)   Relaxes lung airways
C)   Stimulates heart muscle cells
D)   A person feeling energized after drinking a cup of caffeinated coffee
E)   The body's ability to digest a large mealF) A) and B)
G) All of the above

Question 2

A key is placed into a keyhole then turned and the door opens. Which of the following components of cell signaling would best correspond to the keyhole?

Accepted Answer

A)   the hormone
B)   the receptor
C)   conformational change in the receptor once bound to the hormone
D)   signal transduction
E)   the cell responseF) A) and B)
G) All of the above

Question 3

Which of the following statements about steroid receptors is FALSE?

Accepted Answer

A)   The receptors undergo a conformational change after binding the steroid.
B)   The receptors are localized to the plasma membrane.
C)   Once the steroid binds the receptor, the steroid/receptor complexes dimerize.
D)  Steroid receptors act as transcriptional factors, regulating the expression of certain genes and the subsequent production of proteins.
E)   Steroid receptors are localized to either the cytoplasm or nucleus.F) A) and D)
G) A) and C) B

Question 4

What do we call molecules involved in long-distance signaling?

Accepted Answer

A)   kinases
B)   transcription factors
C)   hormones
D)   response elements
E)   receptorsF) B) and E)
G) B) and C)

Question 5

The production of second messengers in signal transduction offers at least two advantages, speed and

Accepted Answer

A)   specificity.
B)   amplification.
C)   one-to-one stochiometry.
D)   reversibility.
E)   affinity.F) A) and B)
G) B) and C)

Question 6

Which of the following is TRUE of ligand-gated ion channels?

Accepted Answer

A)   They bind ions with high affinity.
B)   They tend to allow any ion to pass through the channel.
C)   The intracellular domain of the channel contains the binding site for the ligand.
D)   They open upon binding the ligand to allow specific ions to pass through them.
E)   Ligand binding closes the channels preventing further ion passage through the channel.F) C) and D)
G) A) and E)

Question 7

A hormone binds a receptor and activates the cAMP signal transduction pathway ultimately leading to the cell response. Which of the following is NOT a likely mechanism for reversing (or shutting off)  cAMP transduction?

Accepted Answer

A)   The hormone dissociating from the receptor.
B)   The GTP on the alpha subunit of the G protein is hydrolyzed to GDP.
C)   Activate phosphodiesterase.
D)   Activate adenylyl cyclase.
E)   Protein phosphatases remove phosphates from proteins initially activated by protein kinase A.F) C) and E)
G) C) and D)

Question 8

Hormones regardless of whether they operate locally or at long distances must bind a receptor to elicit a cell response.

Accepted Answer

A) True 
 B)False  True

Question 9

During exposure to elevated glucose, a yeast cell's membrane glucose transporters will rapidly increase so the cell can import glucose. Which would represent the signal for the yeast cell?

Accepted Answer

A)   glucose transporters
B)   glucose receptors
C)   glucose
D)   glucose transport into the cell
E)   glucose kinaseF) A) and B)
G) A) and C)

Question 10

Ligands that promote cell death are typically produced on the surface of cells of the immune system that recognize abnormal cells and target them for destruction.

Accepted Answer

A) True 
 B)False

Question 11

What do enzyme-linked receptors and growth factor receptors have in common?

Accepted Answer

A)   Both possess kinase activity when bound to a hormone.
B)   Both regulate specific G proteins when bound to a hormone.
C)   Both act as transcriptional factors.
D)   Both regulate the transport of ions through channels.
E)   Both seldom affect the expression of genes within the nucleus.F) B) and D)
G) All of the above A

Question 12

The KD or dissociation constant between a receptor and its hormone/ligand is

Accepted Answer

A)   a measure of the binding affinity the receptor has for the hormone.
B)   the hormone concentration where half the receptors are bound to hormone.
C)   the hormone concentration where all of the receptors are bound to hormone.
D)   both a measure of the binding affinity the receptor has for the hormone and the hormone concentration where half the receptors are bound to hormone.
E)   both a measure of the binding affinity the receptor has for the hormone and the hormone concentration where all the receptors are bound to hormone.F) A) and D)
G) A) and C)

Question 13

The type of cellular response that is caused by a given signaling molecule depends on the type of cell responding to the signal.

Accepted Answer

A) True 
 B)False

Question 14

Apoptosis can occur via both intrinsic and extrinsic pathways.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following represents a long-distance signaling mechanism?

Accepted Answer

A)   contact-to-contact signaling
B)   intercellular signaling
C)   autocrine signaling
D)   paracrine signaling
E)   endocrine signalingF) All of the above
G) A) and B)

Question 16

G proteins and Ras are activated when bound to guanosine diphosphate.

Accepted Answer

A) True 
 B)False

Question 17

If IP3 binds a Ca2+ ligand-gated ion channel in the endoplasmic reticulum then cytosolic Ca2+ levels will rise in the cell.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following receptor and signal transduction molecules are mismatched?

Accepted Answer

A)   sensor kinase receptor (NarQ) : NarL
B)   G-protein coupled receptor: adenylyl cyclase
C)   G-protein coupled receptor: phospholipase C
D)   enzyme linked receptors: protein kinase
E)   steroid receptor: calciumF) A) and E)
G) None of the above

Question 19

Various cells in the body respond to the hormone epinephrine in various ways due to _____.

Accepted Answer

A)   cellular respiration
B)   metabolism
C)   phosphodiesterase
D)   protein kinases
E)   differential gene regulationF) B) and E)
G) A) and E)

Question 20

A key is placed into a keyhole then turned and the door opens. Which of the following components of cell signaling would best correspond to turning the key?

Accepted Answer

A)   the hormone
B)   the receptor
C)   conformational change in the receptor once bound to the hormone
D)   signal transduction
E)   the cell responseF) D) and E)
G) B) and E)

Exam 9: Cell Communication

Which of the following is not an effect of epinephrine throughout the body?

Correct AnswerverifiedShow Answer

A key is placed into a keyhole then turned and the door opens. Which of the following components of cell signaling would best correspond to the keyhole?

Correct AnswerverifiedShow Answer

Which of the following statements about steroid receptors is FALSE?

Correct AnswerverifiedB

What do we call molecules involved in long-distance signaling?

Correct AnswerverifiedShow Answer

The production of second messengers in signal transduction offers at least two advantages, speed and

Correct AnswerverifiedShow Answer

Which of the following is TRUE of ligand-gated ion channels?

Correct AnswerverifiedShow Answer

A hormone binds a receptor and activates the cAMP signal transduction pathway ultimately leading to the cell response. Which of the following is NOT a likely mechanism for reversing (or shutting off) cAMP transduction?

Correct AnswerverifiedShow Answer

Hormones regardless of whether they operate locally or at long distances must bind a receptor to elicit a cell response.

Correct AnswerverifiedTrue

During exposure to elevated glucose, a yeast cell's membrane glucose transporters will rapidly increase so the cell can import glucose. Which would represent the signal for the yeast cell?

Correct AnswerverifiedShow Answer

Ligands that promote cell death are typically produced on the surface of cells of the immune system that recognize abnormal cells and target them for destruction.

Correct AnswerverifiedShow Answer

What do enzyme-linked receptors and growth factor receptors have in common?

Correct AnswerverifiedA

The KD or dissociation constant between a receptor and its hormone/ligand is

Correct AnswerverifiedShow Answer

The type of cellular response that is caused by a given signaling molecule depends on the type of cell responding to the signal.

Correct AnswerverifiedShow Answer

Apoptosis can occur via both intrinsic and extrinsic pathways.

Correct AnswerverifiedShow Answer

Which of the following represents a long-distance signaling mechanism?

Correct AnswerverifiedShow Answer

G proteins and Ras are activated when bound to guanosine diphosphate.

Correct AnswerverifiedShow Answer

If IP3 binds a Ca2+ ligand-gated ion channel in the endoplasmic reticulum then cytosolic Ca2+ levels will rise in the cell.

Correct AnswerverifiedShow Answer

Which of the following receptor and signal transduction molecules are mismatched?

Correct AnswerverifiedShow Answer

Various cells in the body respond to the hormone epinephrine in various ways due to _____.

Correct AnswerverifiedShow Answer

A key is placed into a keyhole then turned and the door opens. Which of the following components of cell signaling would best correspond to turning the key?

Correct AnswerverifiedShow Answer

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B

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True

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A

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If IP₃ binds a Ca²⁺ ligand-gated ion channel in the endoplasmic reticulum then cytosolic Ca²⁺ levels will rise in the cell.

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